/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.method.support;

import org.springframework.core.MethodParameter;
import org.springframework.lang.Nullable;
import org.springframework.web.context.request.NativeWebRequest;

/**
 * Strategy interface to handle the value returned from the invocation of a
 * handler method .
 *
 * @author Arjen Poutsma
 * @see HandlerMethodArgumentResolver
 * @since 3.1
 */
public interface HandlerMethodReturnValueHandler {

    /**
     * Whether the given {@linkplain MethodParameter method return type} is
     * supported by this handler.
     *
     * @param returnType the method return type to check
     * @return {@code true} if this handler supports the supplied return type;
     * {@code false} otherwise
     */
    boolean supportsReturnType(MethodParameter returnType);

    /**
     * Handle the given return value by adding attributes to the model and
     * setting a view or setting the
     * {@link ModelAndViewContainer#setRequestHandled} flag to {@code true}
     * to indicate the response has been handled directly.
     *
     * @param returnValue  the value returned from the handler method
     * @param returnType   the type of the return value. This type must have
     *                     previously been passed to {@link #supportsReturnType} which must
     *                     have returned {@code true}.
     * @param mavContainer the ModelAndViewContainer for the current request
     * @param webRequest   the current request
     * @throws Exception if the return value handling results in an error
     */
    void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType,
                           ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception;

}
